1. Field of the Invention
This invention pertains to instruments used for surgical procedures. More particularly, the present invention is directed to improved bipolar surgery forceps having irrigated tips.
2. Description of the Related Art
Bipolar Cautery Electro-Mechanical Instruments (“bipolar instruments”) have many uses in modern surgical practice including dissection and hemostatis and the like. The basic structure of these bipolar surgical instruments includes two elongated members or arms that are connected at one, i.e. the proximal, end of the members. The members are coupled to an alternating current power source for supplying an electrical potential across the conductive tips which are defined at the other (i.e. distal) ends of the members. In operation, these bipolar instruments pass a high frequency AC electrical current between the conductive tips which are placed into contact with patient tissue or vessels. Each tip of the bipolar instrument alternately functions as an active and a ground electrode to provide a more accurate transfer and delivery, to the tissue, of electrical energy than that attainable using Monopolar Electro-Mechanical Instruments.
Early versions of bipolar instruments were powered by spark-gap type electrical generators but exhibited poor cautery of animal tissue, as for example human tissue. Dr. Leonard Malis subsequently developed an improved pulse generator (the current commercial model of which is the CMC II, manufactured by Codman Surgical Products of Raynahm, Mass.) and various types of bipolar tips that have notably improved tissue cautery using bipolar instruments.
To assure electrical communication and contact between the tips of the bipolar instrument and the living tissue, and to also cool the instrument tips, a medical assistant would typically drip a saline-containing fluid onto the site of the surgery during the cautery procedure. Even so, the heat generated at the tip of the bipolar instrument and the effect of the electric current applied directly to the patient's tissue would convert blood on and in contact with the bipolar instrument tips into a “char” formed of heated proteins, and this char would collect on the instrument tips. The accumulated char would cause the tips(s) of the instrument to stick or adhere to the tissue being cauterized, which can prove disastrous if the tissue is (for example) a delicate and vital blood vessel. The char accumulating on the tips also increased the resistance to the flow of electrical current, thereby reducing the operating effectiveness of the bipolar instrument.
To counter the effects of accumulating char, a surgeon using such prior art bipolar instruments would need to periodically halt the cautery procedure and hand the bipolar instrument to an assisting or scrub nurse for cleaning of the instrument tips on a fairly frequent basis, typically as much as once or more each minute. Later and current bipolar instruments have sought to avoid this requirement for frequent cleaning of the tips by incorporating an irrigation tube mounted to or otherwise defined along one of the two elongated members for directly delivering irrigation fluid to the distal tip of that member or arm through the tube. With the irrigation tube connected to a pump, a surgeon controlling the pump is then capable of providing a more precise flow of irrigation fluid to the tissue. This frees up the scrub nurse who could then provide more meaningful assistance to the surgeon performing the cautery procedure. More importantly, the provision of a constant, controlled flow of irrigation fluid to one of the instrument tips markedly diminished the accumulation of char on the instrument, thus facilitating the performance of the surgery by lessening, although not eliminating, the need to regularly halt the surgical or cautery procedure for cleaning of the instrument tips by an assisting nurse. As a consequence, depending on the particular tissue being cauterized and the degree of electrical energy or power being delivered via this improved bipolar instrument, the distal tips would now need to be cleaned only every 3 to 5 minutes during a surgical procedure.
Accordingly, there is a need for a bipolar surgery forceps which can further reduce the build up of char on the forceps ends, thereby requiring less frequent tip cleaning than is required in heretofore known forceps.